Why do the Southern Baptists still exist?

I am just curious why a sub-denomination that was founded on the lie that the Bible sanctions the use of slaves was allowed to continue and grow after the end of slavery, even up until today. I understand many have denounced slavery and racism, but that is not enough! The ENTIRE purpose of the Southern Baptists being called southern baptists was to separate the slave owning 'christian' from the non slave owning christian. As we haven't had slavery in just under a century, why have we had southern baptists for over a century?